JP2002172599A - Nanotube cartridge and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To realize a method capable of manufacturing a nanotube cartridge at low cost by a simple operation without using an electrophoresis method. SOLUTION: In the method for manufacturing a nanotube cartridge A according to the present invention, a large number of nanotubes 4 are attached to the surface of a holder 10 (6), and the knife edge is made to float with the cutting edge 8a in contact with the surface. The nanotubes 8 on the holder surface are gathered on the side of the cutting edge 8a while the knife edge 8 is relatively moved in the tilting direction while the cutting edge 8a is kept in contact with the cutting edge 8a, and is protruded from the cutting edge 8a. It is characterized in that the nanotubes 4 are aligned with the cutting edge 8a of the knife edge 8. In order to attach the nanotubes 4 to the surface of the holder 10 (6), the nanotubes 4 are accommodated in the container 2 and the container 2
Since it is only necessary to put the holder 10 (6) into the container and vibrate the whole container, the nanotube cartridge A can be manufactured easily and at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nanotube cartridge used for manufacturing a nanotube probe by transferring a nanotube protruding from a cutting edge of a knife edge to a pyramid portion of a cantilever. The present invention relates to a nanotube cartridge capable of easily disposing a nanotube at a cutting edge and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, scanning probe microscopes (SPM) such as a tunnel microscope (STM) and an atomic force microscope (AFM) capable of detecting physical property information of a sample surface at an atomic level have been developed. To obtain physical property information on the sample surface using this SPM, a probe that directly contacts the sample surface and detects the information is required.

Conventionally, this probe has been formed of a semiconductor cantilever in which a protruding portion is formed on a cantilever portion and the tip of the protruding portion is sharpened. The sharp tip of this protruding part becomes the probe point, and this tip is brought into contact with the sample surface to detect physical and chemical interactions with the sample surface, and to obtain atomic structure information, magnetic information, functional group information and electronic information And other physical property information.

It is natural that the resolution of physical property information increases as the probe point becomes sharper. However, even if the tip of the protruding portion is sharpened by a semiconductor technique, it is difficult at present technology level to reduce the diameter of the tip to several tens nm or less. Under these circumstances, carbon nanotubes were discovered, and
Dai et al. Are NATURE (Vol. 384), 14 No.
Vember 1996), and came to propose a carbon nanotube probe in which carbon nanotubes are attached to the protrusions.

[0005] The diameter D of the carbon nanotube is about 1 nm.
To several tens of nm, and the axial length L is several μm. The aspect ratio (L / D) reaches several hundreds to several thousands, and has an optimum property as a probe for a scanning probe microscope. However, since the conventional carbon nanotube probe has a structure in which the carbon nanotube is simply attached to the protrusion, the carbon nanotube is dropped from the protrusion and is probed only by scanning the carbon nanotube several times over the sample surface. There was a weak point that the needle action disappeared.

Therefore, the present inventors have invented two methods for firmly fixing the carbon nanotube to the protrusion. The first is a method of coating and fixing the carbon nanotube on the surface of the protruding portion with a coating film.
It is published as 0-227435. The second is,
A method of fusing a base end portion of a carbon nanotube to a surface of a protruding portion by irradiating an electron beam or applying a current thereto is disclosed in
No. 00-249712. In these publications, the present invention has been extended to a nanotube probe using not only carbon nanotubes but also general nanotubes such as BN-based nanotubes (boron nitride) and BCN-based nanotubes (boron carbonitride).

In these publications, a nanotube cartridge in which carbon nanotubes are arranged in a protruding manner on a knife edge is used when manufacturing a carbon nanotube probe. Hereinafter, a method for manufacturing a conventional nanotube cartridge will be described.

First, a carbon nanotube (C) was prepared by the electrophoresis method disclosed in JP-A-2000-72422.
NT). The CNT can be purified by dispersing the carbon mixture in the electrophoresis liquid and applying a DC voltage or an AC voltage. When a DC voltage is applied, C
NTs are arranged in series. When an AC voltage is applied, the CNTs are arranged in series on both the cathode and the anode due to the formation of a non-uniform electric field. This electrophoresis method can be used for purification of not only carbon nanotubes but also BCN-based nanotubes and BN-based nanotubes. Therefore, the carbon nanotubes are hereinafter referred to as nanotubes.

Next, a process of dispersing the purified nanotubes in a dispersion liquid and attaching the nanotubes to a knife edge by electrophoresis will be described. FIG. 11 is a manufacturing process diagram of a nanotube cartridge using a direct current electrophoresis method. The electrophoresis liquid 20 in which the nanotubes are dispersed is placed on a glass substrate 21.
In the hall. Knife edges 22, 23 in the liquid
Are arranged facing each other, and a DC power supply 18 is applied. The knife edges 22, 23 have a structure having sharp cutting edges 22a, 23a at the tips. In the electrophoresis solution 20, there are countless small nanotubes which are not visible to the naked eye but are extremely small. The nanotubes are charged by contact with the electrophoresis running liquid and move by an electric field. When the electrophoresis running solution is isopropyl alcohol, the nanotubes are orthogonally attached to the cutting edge 22a of the knife edge 22 of the cathode. This arrangement can be confirmed with an electron microscope.

FIG. 12 is a view showing a manufacturing process of a nanotube cartridge using an alternating current electrophoresis method. The configuration is the same as that of FIG. 11, except that the AC power supply 19 is applied via the amplifier 26. An inhomogeneous electric field acts between the two poles. An elongated object such as a nanotube migrates when the polarization charge induced in the nanotube feels a non-uniform electric field. In this case, the amorphous particles cannot move. Therefore, unlike the direct current method, the alternating current method also has the ability to sort particles. Even if a non-uniform electric field is not intentionally formed, a local non-uniform electric field is actually formed, so that electrophoresis can be realized. In this example, an AC of 5 MHz and 90 V is applied. The nanotubes adhere to the knife edges 22a and 23a of the knife edges of both electrodes in a perpendicular manner.

FIG. 13 is a conceptual diagram of a completed nanotube cartridge. The nanotube cartridge A is composed of a knife edge 23 and a nanotube 4 attached to the cutting edge 23a in a substantially orthogonal manner. Some of the nanotubes 4 are not only orthogonal to the cutting edge 23a but also oblique. In some cases, the plurality of nanotubes 4 are gathered and attached in a bundle.

FIG. 14 is a diagram of an apparatus for transferring nanotubes to an AFM cantilever. The cantilever 27 includes a cantilever portion 28 and a protruding portion 29 formed at the tip thereof.
It is a member made of silicon. The nanotube cartridge A is arranged so that the nanotube 4 faces the protrusion 29. The cantilever 27 can adjust XYZ three-dimensional movement, and the nanotube cartridge A can move XYZ two-dimensionally. By these movement adjustments, the nanotubes 4 are moved so that the nanotube tip region 4c adheres to the protrusion 29. These operations are performed while enlarging and projecting in the electron microscope room 30.

FIG. 15 is a schematic view of a completed nanotube probe. The base end 4 b of the nanotube 4 is fixed to the protrusion 29 by coating and / or fusion. The distal end region 4c becomes the base end 4b. The tip 4a of the nanotube 4 serves as a probe, and is placed in contact with the sample surface and A
Physical property information is detected by FM operation or the like.

[0014]

It has been found that the nanotube probe thus completed can detect a high-resolution image of the sample surface by the excellent aspect ratio of the nanotube 4. In addition, the progress of research during this period has resulted in many achievements in various fields such as physics, chemistry, and biology.

As described above, a nanotube cartridge A must be used to manufacture the nanotube probe B even though the nanotube probe B has excellent properties. However, since the nanotube cartridge A is formed by an electrophoresis method, not only requires advanced technology, but also requires a complicated process using a large number of members, the cost becomes high, and the spread of the nanotube probe B becomes wide. It was a cause of inhibition.

Accordingly, an object of the present invention is to realize a method capable of producing a nanotube cartridge at a low cost with a simple operation without using an electrophoresis method.

[0017]

According to the first aspect of the present invention, a large number of nanotubes are adhered to the surface of a holder, and a knife edge is inclined with respect to the surface so that the main body is floated with a cutting edge in contact with the surface. The knife edge is relatively moved in the inclined direction while the blade edge is kept in contact, the nanotubes on the holder surface are collected on the blade edge side, and the nanotubes are aligned with the blade edge of the knife edge while protruding from the blade edge. Is a method for manufacturing a nanotube cartridge.

The invention according to claim 2 is the method for manufacturing a nanotube cartridge according to claim 1, wherein the holder is a knife edge having a cutting edge, and a large number of nanotubes are adhered to the knife edge surface.

According to a third aspect of the present invention, the holder is a semiconductor wafer or a semiconductor chip cut out from the semiconductor wafer, and a large number of nanotubes are attached to the surface of the semiconductor wafer or the semiconductor chip. This is a method for manufacturing a nanotube cartridge.

According to a fourth aspect of the present invention, a large number of nanotubes are attached to the surface of the knife edge, and the knife edge surface to which the nanotubes are attached is obliquely arranged so as to face the holder surface. This is a method for manufacturing a nanotube cartridge.

According to a fifth aspect of the present invention, there is provided the method for manufacturing a nanotube cartridge according to the first aspect, wherein a voltage is applied between the holder and the knife edge so that the nanotube is easily attached to the cutting edge of the knife edge.

According to a sixth aspect of the present invention, there is provided the nanotube according to the first aspect, wherein the nanotubes are housed in a container, the holder is put into the container, and the whole container is vibrated to attach the nanotubes to the surface of the holder. It is a manufacturing method of a cartridge.

According to a seventh aspect of the present invention, a large number of nanotubes are adhered to the surface of the holder, and the knife edge is arranged obliquely with respect to the surface so that the main body floats while the cutting edge is in contact with the surface. A nanotube cartridge, wherein nanotubes on the holder surface are collected on the blade edge side while the edge is relatively moved in the inclined direction, and the nanotubes are aligned with the blade edge of the knife edge while protruding from the blade edge.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a nanotube cartridge according to the present invention.

FIG. 1 is a sectional view of a container containing nanotubes. The container 2 may be any container that can accommodate the nanotubes 4, and in this embodiment, a screw tube is used. The nanotube 4 is, for example, a carbon nanotube generated by an arc discharge method, and has a cross-sectional diameter of 1 nm to several tens nm and an axial length of 1 μm to 5 μm.

As the nanotube 4, an arbitrary nanotube such as a BN-based nanotube and a BCN-based nanotube other than the carbon nanotube is used. BN-based nanotubes are produced by placing carbon nanotubes together with B ₂ O ₃ powder in a crucible and heating in N ₂ gas, where most of the C atoms are replaced by B and N atoms. Also, BC
The N-based nanotube is produced, for example, by packing a mixed powder of amorphous boron and graphite in a graphite rod and evaporating the mixed powder in N ₂ gas. It has a structure in which a part of C atoms is replaced by B atoms and N atoms. In addition, nanotubes generated by various methods are applied to the present invention.

FIG. 2 is a schematic view of putting a holder into a container containing nanotubes. After accommodating the nanotubes 4 in the container 2, the holder 10 for attaching the nanotubes to the surface is put into the container 2 in the direction of arrow a. Although there are various types of holders 10, any type can be used as long as the nanotubes 4 can be attached thereto. FIG. 2 illustrates a knife edge 6 having a cutting edge 6a and a semiconductor wafer 7.

The knife edge 6 may be any substrate as long as it has a sharp cutting edge 6a and can attach the nanotubes 4 to the main body surface. For example, a razor blade, a cutter knife blade, and the like are listed. The semiconductor wafer 7 is a substrate such as a thin silicon wafer. In addition, a semiconductor chip or the like formed by cutting a semiconductor wafer can be used as the holder 10.

FIG. 3 is a schematic diagram of vibrating the whole container after the holder is inserted. The holder 10 is buried in the nanotube 4 of the container 2. When the container 2 is reciprocated in the direction of arrow b in this state, the nanotubes 4 come into contact with the surface of the holder 10 while rubbing, and a large number of nanotubes 4 adhere to the surface of the holder 10 by electrostatic force.

FIG. 4 is a plan view of a holder to which nanotubes are attached. A large number of nanotubes 4 are attached to the knife edge 6 used as the holder 10 and the surface of the semiconductor wafer 7 in all directions. As described above, since the nanotube 4 is merely attached to the holder 10, the nanotube 4 is placed on the holder 10.
Can be easily moved in a specific direction.

FIG. 5 is an explanatory view of a method of collecting nanotubes attached to a knife edge at a cutting edge. Knife edge 6
The nanotubes 4 are oriented in all directions and adhere to the upper surface 6b of the substrate. The cutting edge 6a faces rightward.
An unused knife edge 8 on which no nanotubes are adhered is overlaid on the knife edge 6 such that the cutting edge 8a faces left.

Near the left edge of the knife edge 6, a cutting edge 8a
And the knife edge 8 is arranged so as to rise to the right and rise obliquely to the knife edge 6 at a small inclination angle. The knife edge 6 is held stationary, and the cutting edge 8
The knife edge 8 is moved in the direction of the arrow c with the contact a. Conversely, the knife edge 6 may be moved in the opposite direction, for example, the knife edge 6 and the knife edge 8 may be relatively moved in a state where the cutting edge is in friction. By this relative movement, the nanotubes 4 on the knife edge 6 are collected near the cutting edge 6a and the cutting edge 8a.

FIG. 6 is an enlarged view of the oblique arrangement of the knife edges. As shown in the figure, since the cutting edge 8a has a curvature when viewed microscopically, when the cutting edge 8a is brought into contact with the upper surface 6b of the knife edge 6, the lower surface 8
b is inclined so as to have a required inclination angle with respect to the upper surface 6b. When the knife edge 8 is moved in the direction of the arrow c, the nanotubes 4 on the upper surface 6b are swept rightward by the cutting edge 8a.
Gather near the cutting edge 6a and the cutting edge 8a.

FIG. 7 is a perspective view of a main part of the completed nanotube cartridge. The nanotube 4 is placed on the upper surface of the cutting edge 6a, and the nanotube 4 is placed on the lower surface of the cutting edge 8a. The nanotube 4 is oriented in all directions on the upper surface 6b of the knife edge 6, but by moving the knife edge 8 in the direction c, the direction of the nanotube 4 is automatically aligned in the direction of the arrow c. This direction c is the vertical direction of the cutting edges 6a and 8a. Therefore, the nanotubes 4 are arranged to protrude vertically from the cutting edge 6a and the cutting edge 8a.

As described above, the nanotube cartridge A has the nanotubes 4 arranged so as to protrude vertically from the cutting edges 6a, 8a of the knife edges 6, 8. By this operation, two nanotube cartridges A, A are simultaneously manufactured.

Since the nanotubes 4 are also attached to the lower surface 6c of the knife edge 6, the nanotubes 4 on the lower surface 6c are swept and collected by the same operation, so that two more nanotube cartridges can be manufactured. When the number of nanotubes in the nanotube cartridge A is small, the number of nanotubes can be increased by sweeping and collecting the nanotubes again at the knife edge.

FIG. 8 is an oblique view of the knife edges with a voltage applied between the knife edges. Voltage control circuit V
Are connected to knife edges 6,8. Since the knife edge is made of a conductive metal, a current limiting circuit is provided to prevent an excessive current from flowing. in this way,
When a DC voltage is applied, an electric field is formed between the knife edges 6 and 8, and the nanotube 4 is moved by the electric field force to the cutting edges 6 a and 8.
a.

FIG. 9 is an explanatory view of a method of collecting nanotubes attached to a semiconductor wafer at the cutting edge of a knife edge.
On the surface of the semiconductor wafer 7, the nanotubes 4 are oriented and attached in all directions. An unused knife edge 8 on which no nanotubes are attached on the semiconductor wafer 7
Are overlapped so that the cutting edge 8a faces left.

The blade edge 8a is brought into contact with the surface of the semiconductor wafer 7, and the knife edge 8 is arranged so as to rise rightward so as to be oblique to the semiconductor wafer 7 at a small inclination angle. This situation is the same as in FIGS. When the knife edge 8 is moved in the direction of the arrow d in the state of contact with the cutting edge, the nanotubes 4 are aligned while the axial direction is aligned in the direction of the arrow d.
Are collected on the lower surface of the cutting edge 8a, and the nanotube cartridge A is completed.

FIG. 10 is a perspective view of a main part of the completed nanotube cartridge A. Nanotube 4 has cutting edge 8a
Can be understood from a state in which it protrudes perpendicular to the leading edge of the. In the method of FIGS. 9 and 10, one nanotube cartridge A can be formed by one operation. Further, in this method, nanotubes can be arranged only on one surface of the knife edge.

To attach the nanotubes 4 to the surface of the holder, the nanotubes 4 may be sprinkled on the surface of the holder, or the holder may be inserted into a deposit of the nanotubes 4 and reciprocated. Alternatively, a voltage may be applied between the holder and the nanotube, and the nanotube may be adsorbed on the holder surface by electrostatic force.

The holder used is not limited to a knife edge, a semiconductor wafer, or a semiconductor chip cut out of a semiconductor wafer, but may be any thin member having a clean surface on which nanotubes can be attached.

The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications and design changes without departing from the technical idea of the present invention are included in the technical scope. Absent.

[0044]

According to the first aspect of the present invention, the nanotubes are aligned orthogonally to the blade edge only by moving the knife edge by bringing the blade edge into contact with the holder surface, so that a nanotube cartridge can be manufactured at a stretch by a very simple operation. can do.

According to the second aspect of the present invention, since a knife edge having a cutting edge is used as a holder, two nanotube cartridges can be simultaneously manufactured by one operation, and a method for mass-producing nanotube cartridges can be provided. .

According to the third aspect of the present invention, since a semiconductor wafer or a semiconductor chip is used as a holder, it can be used as a substitute when there is no knife edge.

According to the fourth aspect of the present invention, in addition to the nanotubes on the holder surface, a large number of nanotubes are adhered to the surface of the knife edge, so that the nanotubes can be arranged on the cutting edge with high density.

According to the fifth aspect of the present invention, since a voltage is applied between the holder and the knife edge, the nanotubes can be efficiently attached to the cutting edge of the knife edge, and an efficient method of manufacturing a nanotube cartridge can be achieved. Can be provided.

According to the sixth aspect of the present invention, the nanotubes can be attached to the surface of the holder simply by putting the holder into the container containing the nanotubes and vibrating the container.

According to the seventh aspect of the present invention, a nanotube cartridge in which nanotubes are arranged perpendicular to the blade edge can be manufactured only by moving the knife edge by bringing the blade edge into contact with the holder surface. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a container containing nanotubes.

FIG. 2 is a schematic view of putting a holder into a container containing nanotubes.

FIG. 3 is a schematic diagram of vibrating the entire container after the holder is inserted.

FIG. 4 is a plan view of a holder to which a nanotube is attached.

FIG. 5 is an explanatory diagram of a method of collecting nanotubes attached to a knife edge at a cutting edge.

FIG. 6 is an enlarged view of an inclined arrangement of a knife edge.

FIG. 7 is a perspective view of a main part of the completed nanotube cartridge.

FIG. 8 is an oblique view of a knife edge in a state where a voltage is applied between the knife edges.

FIG. 9 is an explanatory diagram of a method of collecting nanotubes attached to a semiconductor wafer at a blade edge of a knife edge.

FIG. 10 is a perspective view of a main part of the completed nanotube cartridge.

FIG. 11 is a process chart of a nanotube cartridge using a direct current electrophoresis method.

FIG. 12 is a view showing a manufacturing process of a nanotube cartridge using an alternating current electrophoresis method.

FIG. 13 is a conceptual diagram of a completed nanotube cartridge.

FIG. 14 is an apparatus diagram for transferring a nanotube to a cantilever for AFM.

FIG. 15 is a schematic view of a completed nanotube probe.

[Explanation of symbols]

 2: Container 4: Nanotube 6: Knife edge 6a: Blade edge 6b: Upper surface 6c: Lower surface 7: Semiconductor wafer 8: Knife edge 8a: Blade edge 8b: Lower surface 10: Holder 18: DC power supply 19: AC power supply 21: Glass substrate 22 : Knife edge 22a: Blade edge 23: Knife edge 23a: Blade edge 26: Amplifier 27: Cantilever 28: Cantilever part 29: Projection part 30: Electron microscope room A: Nanotube cartridge B: Nanotube probe V: Voltage control circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiji Akita 1248-4, Ikedashitamachi, Izumi-shi, Osaka (72) Inventor Takayoshi Kishida 3-24-19 Kibogaoka, Miyazaki-shi, Miyazaki-shi (72) Inventor Harada Akio 2-7-19 Nishi Nishi, Joto-ku, Osaka City, Osaka

Claims (7)

[Claims] 1. A method in which a large number of nanotubes are attached to the surface of a holder, and a knife edge is arranged at an angle to the surface so as to float the main body with the blade in contact with the surface, and the blade is kept in contact with the surface. A method of manufacturing a nanotube cartridge, comprising: collecting nanotubes on a holder surface on a cutting edge side while relatively moving a knife edge in the tilt direction, and aligning the nanotubes with the cutting edge of the knife edge in a state of protruding from the cutting edge. 2. The method according to claim 1, wherein the holder is a knife edge having a cutting edge, and a large number of nanotubes are adhered to the knife edge surface. 3. The method according to claim 1, wherein the holder is a semiconductor wafer or a semiconductor chip cut out of the semiconductor wafer, and a large number of nanotubes are attached to a surface of the semiconductor wafer or the semiconductor chip. . 4. The method for manufacturing a nanotube cartridge according to claim 1, wherein a large number of nanotubes are attached to the surface of the knife edge, and the knife edge surface to which the nanotubes are attached is inclined so as to face the holder surface. . 5. The method for manufacturing a nanotube cartridge according to claim 1, wherein a voltage is applied between the holder and the knife edge so that the nanotube is easily attached to the cutting edge of the knife edge. 6. The method for producing a nanotube cartridge according to claim 1, wherein the nanotube is accommodated in a container, a holder is put into the container, and the entire container is vibrated to attach the nanotube to the surface of the holder. 7. A large number of nanotubes are attached to the surface of the holder, and the knife edge is arranged to be inclined with respect to the surface so that the main body is floated with the cutting edge in contact with the surface. A nanotube cartridge wherein nanotubes on a holder surface are collected on the blade side while being relatively moved, and the nanotubes are aligned with the blade edge of the knife edge in a state of protruding from the blade edge.